Flat Panel Display

ABSTRACT

Space is decreased in the direction of thickness on a side of a substrates mounted on a back of a flat panel display to adapt requirement for increasing and thinning its size, and most flat panel displays forcibly radiate heat with a fan provided thereon. The present invention provides a flat panel display having fewer heat radiating fans to secure a channel for causing a heat radiating air to flow. Portions where electronic circuit device on a back of a display panel are mounted are divided into three: left; center; and right portions; with a main frame as a border, the electronic circuit device are constructed of four module substrates, the substrate which is the greatest in heating value in the four module substrates (hereinafter referred to as a substrate) is arranged in the center portion and the substrates which are the smallest and the second smallest in heating value therein are arranged in the same portion.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a flat panel display using a displaydevice such as a plasma display panel, and in particular, to a techniquefor improving heat radiation.

(2) Description of the Related Art

A conventional flat panel display using a display device such as aplasma display panel (PDP) generally displays an image on the front sideof the display device (hereinafter referred to as a “display panel”) andmounts a large number of electronic mechanical components on the rearside thereof. For this reason, a user who watches an image views thescreen of the panel from the front side thereof.

The flat panel display using the PDP arranges a power supply substrate,a Y sustaining substrate, an X sustaining substrate, a signal processingcircuit, an operation substrate and an external input and outputsubstrate on a face opposite to the screen of the panel, i.e., on therear side thereof and each component is fixed with a holding memberincorporating the PDP. The substrates are connected together with cablesand power supply plugs are also connected together with cables. Theentire components are covered with a protective cover to construct theflat panel display.

The flat panel display using a display device such as the PDP becomeslarger and thinner in a display screen in recent years.

As described in Japanese Patent Application Laid-Open No. 2000-156581,space is decreased in the direction of thickness on the side of thesubstrates mounted on the rear side to adapt requirement for thinning,most flat panel displays forcibly radiate heat with a fan. However,driving the fan raises heating value, and at the same time, increasingthe flat panel display in size also increases heating value and thinningthe display decreases a channel for radiating heat. Merely radiatingheat with a fan is insufficient at present.

If a substrate is dispersed and a cable is long, a relay amplifier isrequired. A magnetic field generated by current flowing temporallyvaries current itself and increases a current value to require a drivingcircuit with a larger driving force, further increasing consumptioncurrent.

In the panel display using the PDP, the panel generates a large amountof electromagnetic waves so that it is highly necessary to beelectromagnetically shielded.

SUMMARY OF THE INVENTION

The present invention provides a flat panel display having fewer heatradiating fans to ensure a channel for causing a heat radiating air toflow.

More specifically, in a flat panel display according to the presentinvention, a flat panel display, comprising,

a display panel and an electronic circuit device which is mounted on aback side surface of said display panel wherein said electronic circuitdevice is constructed four (4) sets of module substrates, each having adifferent heating value, and the back side surface of said display panelis divided into a center portion, a left portion and a right portion,wherein one of said module substrates having the highest heating valueis arranged in said center portion while other module substrates havingthe heating values lower than the highest one of are arranged at leastone of said left portion and said right portion.

Furthermore, in the flat panel display according to the presentinvention, the substrate which is the greatest in heating value isrendered a power supply substrate, the substrate which is the secondgreatest in heating value is rendered a Y sustaining substrate and thesubstrate which is the third greatest in heating value is rendered an Xsustaining substrate. Further, the substrate which is the smallest inheating value mainly includes a signal processing circuit and othersubstrates.

Still furthermore, the flat panel display according to the presentinvention includes: a display panel; a power supply substrate arrangedat the back of the display panel and constructing a power supply foroperating the display panel; and a signal processing substrate arrangedat the back of the display panel and processing a video signal displayedon the display panel; wherein the power supply substrate is arranged atthe center portion of the display panel, the signal processing substrateis arranged at one of the left and the right in the horizontal directionof the display panel and in a position where the signal processingsubstrate does not overlap with the power supply substrate in thevertical direction of the display panel.

Still furthermore, in the flat panel display according to the presentinvention, openings for heat radiation are made at the center of thearrangement and at the upper and the lower portion of a cover of theflat panel display to enable air to be circulated.

According to the present invention, heat can be effectively radiatedeven in a flat panel display whose consumption power increased due toincrease in its size. Furthermore, heat can be effectively radiated evenin a flat panel display whose structure hardly employs a heat radiatingchannel because the display is thinned.

As a second advantage of the present invention, the signal processingcircuit and other substrates are incorporated into the same substrate,so that cable wirings between the substrates are shortened or laid onthe substrate, which decreases the number and the length of cablewirings. This increases available space to easily secure channels forheat radiation. In addition, electromagnetic induction can be lessgenerated to allow reduction in consumption power and improvement infunctions of the display device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear view of one embodiment of a flat panel displayaccording to the present invention;

FIG. 2 is a front view of one embodiment of the flat panel displayaccording to the present invention;

FIG. 3 is a schematic cross section illustrating side elevation of oneembodiment of the flat panel display according to the present invention;

FIG. 4 is a rear view of one embodiment of a flat panel display;

FIG. 5 is a front view of one embodiment of a flat panel display;

FIG. 6 is a schematic cross section illustrating a side configuration ofone embodiment of a flat panel display;

FIG. 7 is a schematic diagram describing one embodiment of flow ofcooling air in the rear face of the flat panel display according to thepresent invention;

FIG. 8 is a schematic diagram describing one embodiment of air intakeand air outlet provided on a cover of the flat panel display accordingto the present invention;

FIG. 9 is a schematic block diagram of a flat panel display; and

FIG. 10 is a rear view of one embodiment of a flat panel displayaccording to the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

The embodiment of the present invention is described below withreference to the accompanied drawings. In each drawing, composingelements having common functions are given the same reference numeralsand duplicate descriptions thereof are omitted.

FIGS. 1 to 6 are diagrams illustrating the configuration of a flat paneldisplay with the PDP as a display device. FIGS. 4 to 6 are diagramsillustrating a configuration inferior in heat radiation. FIGS. 1 to 3are diagrams illustrating an arrangement in which heat radiation isimproved.

FIG. 4 is a rear view of the flat panel display with its cover removed.FIG. 5 is a front view of the flat panel display illustrated in FIG. 4.FIG. 6 is a schematic cross section viewed from the side of the flatpanel display illustrated in FIG. 4. Reference numeral 400 denotes aflat panel display; reference numeral 101 denotes a display panel suchas a PDP display device; reference numeral 102 denotes a frame holdingthe panel; and reference numerals 103 and 104 denote main framesattached to the frame and reinforcing them in the vertical direction asbeams. The main frames 103 and 104 divide the back of the panel 101 intothe left portion, the center portion and the right portion in thehorizontal direction.

Reference numeral 105 denotes a power supply substrate mounted in thecenter portion at the back of the display panel 101; reference numeral106 denotes a Y sustaining substrate mounted in the left portion at theback of the display panel 101; reference numeral 107 denotes an Xsustaining substrate mounted in the right portion at the back of thedisplay panel 101; reference numeral 409 denotes a signal processingsubstrate mounted in the center portion at the back of the display panel101 and in the lower portion of the power supply substrate 105;reference numeral 110 denotes a hard disk drive (HDD) unit mounted inthe center portion at the back of the display panel 101 and in the lowerportion of the power supply substrate 105; reference numeral 411 denotesa control substrate mounted in the lower portion of the power supplysubstrate 105 and the signal processing substrate 409 in the centerportion at the back of the display panel 101; reference numeral 112denotes a support on which a flat panel display 400 is rested; referencenumeral 101′ denotes a front surface of the display panel displaying animage which a user views; reference numeral 414 denotes a control panelon the front surface of the display panel 101′ whereby the user operatesthe flat panel display 100; reference numeral 416 denotes an externalstorage device which records or reproduces removal media inserted into aslot and is mounted in the lower portion of the power supply substrate105 and the signal processing substrate 409 in the center portion at theback of the display panel 101; reference numeral 413 denotes a cover forprotecting the flat panel display 100; and reference numeral 115 denotesan attachment fitting for attaching the cover 413 to the main frames 103and 104.

The HDD unit 110 does not always particularly need to be the HDD, butmay be other storage devices, or may not be mounted. The externalstorage device 416 is a digital versatile disk (DVD) or a semiconductormemory recording device and may not be mounted.

In FIGS. 4 to 6, wiring cables for electrically connecting thesubstrates together are omitted from illustration for the sake ofsimplicity. Mechanically attaching, mounting, fixing and holding screwsand screw holes are also omitted from illustration for the sake ofsimplicity. Plural heat radiating fins for directly radiating heat fromheat generating elements such as a power transistor and a centralprocessing unit (CPU) is attached to the power supply substrate 105, theY sustaining substrate 106, the X sustaining substrate 107 and thesignal processing substrate 409. Similarly to the above, the above finsare omitted because the fins are positioned over the substrates in therear view of the flat panel display 400 in FIG. 4 and because theillustration of the fins in the schematic cross section in FIG. 6 makesit difficult to discriminate them from the other composing elements.Forced-cooling blower fans are mounted in spots but are omitted fromillustration for the sake of simplicity.

In FIGS. 4 to 6, at the upper and the lower portion of the cover 413,there are made vent holes for ventilating air for heat radiation. Evenwhen the blower fans are not operated, air heated in the flat paneldisplay 400 escapes from the vent hole at the upper portion of the cover413 and air is supplied from that of the lower portion thereof.

The signal processing substrate 409 and the HDD unit 110 are mountedunderlie the power supply substrate 105 which is the greatest in heatingvalue and the control substrate 411 is mounted under the signalprocessing substrate 409 and the HDD unit 110. The control substrate411, in particular, interrupts the vent hole made in the lower centralportion of the cover 413. For this reason, the vent hole is weak inair-intake force, requiring a forced cooling with the aid of a blowerfan (not shown). Between the substrates, there are laid a large numberof wiring cables (not shown) in the horizontal direction. The wiringcables prevent air from ventilating, thereby sufficient heat radiationcannot be obtained.

Similarly, the external storage device 416 mounted under the Ysustaining substrate 106 which is the second greatest in heatinginterferes with a cooling channel.

Thus, the substrates, the unit and storage device are separatelyarranged, so that the cables connecting them are long and the numberthereof is great. This interferes with the cooling channels and maydeteriorate characteristics of the flat panel display by electromagneticinduction generated if current flows. For this reason, there areprovided an electromagnetic shield or ferrite to take a countermeasureagainst electromagnetic interference (EMI). Providing such anelectromagnetic shield or ferrite interferes with the heat radiatingchannels and leads to increase in production cost.

The configuration of such a flat panel display as described in FIGS. 4to 6 can hardly produce a good effect in terms of heat radiation andmagnetic shield. Then, one embodiment of the present invention as amodification thereof is described below with reference to FIGS. 1 to 3.

FIG. 1 is a rear view the flat panel display with its cover removed.FIG. 2 is a front view of the flat panel display illustrated in FIG. 1.FIG. 3 is a schematic cross section viewed from the side of the flatpanel display illustrated in FIG. 1.

Reference numeral 100 denotes a flat panel display. Reference numeral108 denotes a support frame being a horizontal beam spanning between theframe 102 and the main frame 104 in the right portion at the back of thedisplay panel 101; reference numeral 109 denotes a module substrateincorporating the signal processing substrate, control substrate andexternal storage device supported by the support frame 108, main frame104 and frame 102 and mounted; reference numeral 113 denotes a cover;and reference numeral 114 denotes a control panel attached near themodule substrate 109. The control panel 114 is attached to the rightface which cannot be illustrated in FIG. 3 and contacts the modulesubstrate 109. The HDD unit 110 does not always particularly need to bethe HDD, but may be other storage devices, or may not be mounted. Thesignal processing substrate 109 subjects a video signal displayed on thedisplay panel 101 to various signal processing such as, for example,contrast correction process, color correction process, frame rateconversion and interlace-to-progressive scanning conversion.

In FIGS. 1 to 3, wiring cables for electrically connecting thesubstrates together are omitted from illustration for the sake ofsimplicity. Mechanically attaching, mounting, fixing and holding screwsand screw holes are also omitted from illustration for the sake ofsimplicity. Plural heat radiating fins for directly radiating heat fromheat generating elements such as a power transistor and a centralprocessing unit (CPU) are attached to the power supply substrate 105,the Y sustaining substrate 106 being a first driving substrate fordriving the display panel 101, the X sustaining substrate 107 being asecond driving substrate for driving the display panel 101 and themodule substrate 109. Similarly to the above, the above fins are omittedbecause the fins are positioned over the substrates in the rear view ofthe flat panel display 100 in FIG. 1 and because the illustration of thefins in the schematic cross section in FIG. 3 makes it difficult todiscriminate them from the other composing elements. Forced-coolingblower fans are not mounted in the present embodiment.

In FIGS. 1 to 3, at the upper and the lower portion of the cover 113,there are made vent holes for ventilating air for heat radiation. Airheated in the flat panel display 100 escapes from the vent hole at theupper portion of the cover 113 and air is supplied from that of thelower portion thereof.

In the present embodiment, as is clear from the figure, the power supplysubstrate 105 which is the greatest in heating value generation andgenerates a power supply voltage (supplied to the Y sustaining substrate106, the X sustaining substrate 107 and the signal processing substrate109) for operating the display panel 101 is arranged in the centerportion at the back the display panel 101. Aside from the HDD unit 110,there are not arranged such a substrate, projection and shielding asinterfere with a cooling or heat-radiating channel under the powersupply substrate 105. In the conventional art described, for example, inJapanese Patent Application Laid-Open No. 2000-156581, the signalprocessing substrate and the like are arranged under the power supplysubstrate. The power supply substrate and the signal processingsubstrate are arranged side by side in the upper and the lower portionat the center of the display panel respectively. In the presentembodiment, however, the signal processing substrate 109 is arranged atone of the left and the right in the horizontal direction of the displaypanel 101 instead of at the center of the display panel 101 and in aposition where the signal processing substrate 109 does not overlap withthe power supply substrate 105 in the vertical direction of the displaypanel 101. In other words, the signal processing substrate 109 isarranged outside the area enclosed by the straight lines in which theleft- and the right-hand side of the power supply substrate are extendedin the vertical direction. Air entering the flat panel display 100 fromthe center lower portion thereof smoothly flows toward the power supplysubstrate 105 as cooling air without going through the signal processingsubstrate 109 (that is to say, the signal processing substrate 109 doesnot interfere with or disturb the air) to efficiently radiate heat.Furthermore, the signal processing substrate, control substrate andexternal storage device are incorporated in the module substrate 109 toreduce the number of cables connecting the above components together andof cables laid under the power supply substrate 105, causing smoothcooling air to flow, which radiates heat around the power supplysubstrate 105. Still furthermore, reduction in the number of cables andin the length thereof enables preventing the deterioration ofcharacteristics of the flat panel display 100 due to electromagneticinduction. The electromagnetic shield and ferrite for considering EMIregulation can be reduced in number as much as possible to allowreduction in production cost.

In the present embodiment, the signal processing substrate 109 isarranged on the side opposite to the Y sustaining substrate 106comparatively greater in heating Value than the X sustaining substrate107, i.e., under the X sustaining substrate 107. This enables the signalprocessing substrate 109 to be protected thermally from the Y sustainingsubstrate 106 and cooling air entering from the lower portion of theflat panel display 100 to flow toward the Y sustaining substrate 106without the interference of the signal processing substrate 109. Since alarge number of fins is provided on the Y sustaining substrate 106because it is comparatively greater in heating Value and since the Ysustaining substrate 106 is larger in a circuit area than the Xsustaining substrate 107, the signal processing substrate 109 isarranged on the side of the X sustaining substrate 107 where the signalprocessing substrate 109 can be easily arranged in terms of space.

A circuit other than the signal processing substrate 109 may be arrangedunder the X sustaining substrate 107. For example, a slot into which arecording medium such as a removable HDD is inserted and a removable HDDcontrolling substrate for controlling writing a video signal into andreading it from the recording medium may be stacked on the signalprocessing substrate 109 (more specifically, they may be stacked in thedirection orthogonal to the principal plane of the display panel 101).It is needless to say that other circuit substrates may be stacked onthe signal processing substrate 109 and the removable HDD controllingsubstrate.

FIG. 7 is a schematic diagram describing a channel for cooling air inthe flat panel display 400′ without the HDD unit 410 in theconfiguration of the embodiments in FIGS. 1 to 3. Plural air intakes(not shown) are provided at the lower portion of the cover 113 andplural air outlets (not shown) are provided at the upper portionthereof. The channel is indicated by an arrow. The thicker the arrow is,the higher the air flow rate is. The larger the number of the arrows,the higher the air flow rate. Also in the present embodiment, the signalprocessing substrate 109 is arranged under the lower portion of the Xsustaining substrate 107 and in a position where the signal processingsubstrate 109 does not overlap with the power supply substrate 105 inthe vertical direction of the display panel 101.

As illustrated in FIG. 7, air flowing though cooling fins (not shown) atthe upper portion (on this side of the paper surface) of the powersupply substrate 105 is the highest in flow rate.

A figure enclosed by a circle 700 in FIG. 7 is a schematic cross-sectiontop or bottom view of a substrate. Heat generating elements such aspower transistors are mounted on the cooling fins in FIG. 7 and airpassing through between the cooling fins in the direction of the blackcircle. The black circle is a cross section of the arrow in FIG. 7.

In the present embodiment, the Y sustaining substrate and the Xsustaining substrate are mounted on the left and the right portionrespectively. However, the left and the right are relative. It isneedless to say that the Y and the X sustaining substrate may be mountedon the right and the left portion respectively.

FIG. 8 is a schematic diagram describing one embodiment of the cover 113used in the configuration of the embodiments in FIGS. 1 to 3. Countlesscircular vent holes are made on the entire face of the cover 113. Inparticular, air intakes 811, 812 and 813 are provided at the lowerportion of the cover 113 and air outlets 821, 822 and 823 are providedat the upper portion thereof. Other than the above positions, vent holesare made to urge cooling air to circulate, improving a coolingperformance.

In the embodiment in FIG. 8, plural circular holes are made, but anyshape and size may be provided, and openings with different shape andsize may be combined together. The flat panel display is provided withan opening used as a handle for carrying the display or for fixing. Theopening may be used as a vent hole.

FIG. 9 is a schematic block diagram of a flat panel display using adisplay device such as a PDP. Reference numeral 900 denotes a flat paneldisplay using a display device (panel 901) such as a PDP; referencenumeral 901 denotes a panel; reference numeral 910 denotes a controlunit; reference numeral 920 denotes a display unit; reference numeral911 denotes a control circuit; reference numeral 912 denotes a powersupply circuit; reference numeral 921 denotes a Y sustain pulsegenerator; reference numeral 922 denotes an X sustain pulse generator;reference numeral 923 denotes a level shift circuit; reference numeral924 denotes a scan driver; and reference numeral 925 denotes an addressdriver.

In FIG. 9, the scan driver 924 scans and drives all the Y electrodes ofthe panel 901 on a sub-field basis. The address driver 925 constructs anaddress pulse voltage whose timing corresponds to an image signal. Anaddress electrode is driven by the address pulse voltage to address thedisplay cell of the panel 901 on a sub-field basis. The X sustain pulsegenerator 922 generates a sustain pulse for driving the X electrode. TheY sustain pulse generator 921 generates a sustain pulse for driving theY electrode. The level shift circuit 923 is a photocoupler. The controlcircuit 911 controls the Y sustain pulse generator 921, the X sustainpulse generator 922, the level shift circuit 923, the scan driver 924and the address driver 925. The power supply circuit 912 is equippedwith a DC/DC converter and supplies each composing element of the flatpanel display 900 with power.

The composing elements in FIG. 9 can be associated with those in FIG. 1as follows: the display panel 901 is associated with the display panel101; the control circuit 911 with the module substrate 109; the powersupply circuit 912 with the power supply substrate 105; the Y sustainpulse generator 921 with the Y sustaining substrate 106; the X sustainpulse generator 922 with the X sustaining substrate 107; and the levelshift circuit 923 with the Y sustaining substrate 106. The scan driver924 and the address driver 925 are not illustrated in FIG. 1.

FIG. 10 is a diagram illustrating a rear view of FIG. 1 to which thescan driver 924 and the address driver 925 are added. As illustrated inFIG. 10, the scan drivers 1001 and 1002 are mounted on both sides ofdisplay panel 101 and the address driver 1003 is mounted at the lowerportion thereof.

As described above, the embodiment enables constructing such a structureas to cause cooling air to easily flow thereinto even in a flat paneldisplay whose consumption power increased due to increase in its size oreven in a flat panel display whose structure hardly employs a heatradiating channel because the display is thinned, so that heat can beeffectively radiated.

The signal processing circuit and other substrates are incorporated intothe same substrate, so that cable wirings between the substrates areshortened or laid on the substrate, which decreases the number and thelength of cable wirings. This increases available space to easily securechannels for heat radiation.

Electromagnetic induction can be less generated to allow reduction inconsumption power and improvement in functions of the display device.

1. A flat panel display, comprising a display panel; and an electroniccircuit device, which is mounted on a back side surface of said displaypanel, wherein said electronic circuit device is constructed four (4)sets of module substrates, each having a different heating value, andthe back side surface of said display panel is divided into a centerportion, a left portion and a right portion, wherein one of said modulesubstrates having the highest heating value is arranged in said centerportion, while other module substrates having the heating values lowerthan the highest one of are arranged at least one of said o left portionand said right portion.
 2. A flat panel display comprising: a powersupply substrate; a Y sustaining substrate; an X sustaining substrate;and other processing substrates; wherein the back of a display panel ofthe flat panel display on which the power supply substrate, the Ysustaining substrate and the X sustaining substrate are mounted isdivided into three: left; center; and right portions; the power supplysubstrate is arranged at the center portion, the Y sustaining substrateis arranged at the left or the right portion and the X sustainingsubstrate and the other processing substrates are arranged at the rightor the left portion where the Y sustaining substrate is not arranged. 3.A flat panel display comprising: a display panel; a power supplysubstrate arranged at the back of the display panel and constructing apower supply for operating the display panel; and a signal processingsubstrate arranged at the back of the display panel and processing avideo signal displayed on the display panel; wherein the power supplysubstrate is arranged at the center portion of the display panel, thesignal processing substrate is arranged at one of the left and the rightin the horizontal direction of the display panel and in a position wherethe signal processing substrate does not overlap with the power supplysubstrate in the vertical direction of the display panel.
 4. The flatpanel display according to claim 3, wherein a first driving substratefor driving the display panel is arranged on one side of the powersupply substrate and a second driving substrate for driving the displaypanel is arranged on the other side thereof when viewing the displaypanel from its back and the signal processing substrate is arrangedunder one of the first and the second driving substrates.
 5. The flatpanel display according to claim 4, wherein the display panel is aplasma display panel.
 6. The flat panel display according to claim 5,wherein the first driving substrate is a Y sustaining substrate, thesecond driving substrate is the X sustaining substrate which is smallerin heating value than the Y sustaining substrate and the signalprocessing substrate is arranged under the X sustaining substrate. 7.The flat panel display according to claim 4, wherein the signalprocessing substrate is connected to a control panel for operating theflat panel display.
 8. The flat panel display according to claim 4,wherein on the signal processing substrate, there are stacked a slotinto which a detachable recording medium is inserted and a substrate forcontrolling writing the video signal into and reading it from therecording medium.
 9. The flat panel display according to claim 4,wherein air entering the flat panel display from the center lowerportion of the flat panel display is supplied to the power supplysubstrate without going through the signal processing substrate.